It hasn't been implemented yet. I think the implementation date was delayed until January 1, 2014. I think the joint committee estimated it will raise $8 billion, which isn't really a whole lot of revenue considering the global spread of this new law and the compliance costs that are going to have to be incurred by Canadian and other foreign banks. So the jury's still out on FATCA.
On February 14th, 2013. See this statement in context.